This invention relates, in general, to vehicles, and, in particular, to a weight supporting device for a land vehicle.
More specifically, but without restriction to the particular use which is shown and described, this invention relates to an air track apparatus to reduce the unit area loading of highways and the like by vehicles. The air track apparatus herein described is a form of an air cushion device and includes an endless belt means which is operatively coupled to the existing axle and wheels of the vehicle.
Because of frost conditions and the like which are encountered in certain parts of the United States, such as in the Northwest, and in Canada, the load carrying ability of highways and roads is adversely affected. The exposure of the road surfaces to such thermal conditions often necessitates the imposition of regulations to limit the unit area loading imposed by vehicles. Such restrictions are detrimental to the operation of heavy trucks and the like over the highways because such vehicles often exceed these permissible loading levels and can cause damage to the road surface.
In the prior art, several techniques have been employed to overcome the problem of operating trucks and other heavy-duty vehicles over highways subjected to the effects of the frost cycles, or in the case of roadways having low grade surfaces incapable of supporting large loads. One technique has utilized air cushion or ground effect devices by which the wheels of the truck may be partially suspended from contact with the road thereby reducing the loading applied thereto. However, the utilization of a pure air cushion device significantly reduces the ability of an operator to control operation of the vehicle through steering and braking, particularly on slopes, since frictional contact between the vehicle wheels and road surface is drastically reduced. In addition, known air cushion devices require expensive systems capable of generating high levels of air pressure and costly and inconvenient modifications of the vehicle and have yet been satisfactorily employed.